1. Field of the invention
This invention is concerned with the preparation of a polyester filled epoxy resin electrical insulation system for use in lightweight high voltage transformers and capacitors.
2. Description of Prior Art
High voltage power supplies for satellite and other aerospace systems have previously been packaged either in oil or in a block of some hard or rubbery solid potting material. The oil-filled units were very reliable, but heavy due to the oil, case, and bellows unit. The potted units were heavy and larger than necessary since a great deal of the potting block was space empty of components. In addition, the potted units were less reliable than those filled with oil due to the lower electrical breakdown stress of the solid insulation. This lower breakdown stress has been attributed to defects or voids left by the potting process. In order to solve this problem, we have developed a lighter, more reliable solid encapsulation system which has a very high corona inception stress.